如何测试哪个子列表包含特定元素，然后打印该子列表中的元素

Question

File Name: records.csv

Sample file contents:

11, Owen, 17

4, Hank, 18

77, Paul, 10

8, Ryan, 35

12, Patrick, 24

def getFileName():

    fileName = input('Input File Name: ')
    return fileName

def processFile(fileName):

    file = open(fileName, 'r')

    lines = file.readlines()

    fileList = []
    info = []
    pts = []

    for a in lines:
        fileList = a.split(',')
        fileList[-1] = int(fileList[-1])

        info.append(fileList)

    print('-----------------------------------------------')
    print('##\t Player\t             Points')
    print('-----------------------------------------------')

    for a in info:
        print(a[0],'.','\t', a[1],'\t\t', a[-1], sep='')
    print('-----------------------------------------------')

    for a in info:
        pts.append(a[-1])

    maxPts = max(pts)


    # Find maxPts in one of the 5 sublist, and make a brand new list of it.


    print('Top Scorer:', 'Points:', maxPts)

    file.close()

def main():

    fileName = getFileName()
    processFile(fileName)

main()

Like mentioned in the note above, the list, 'info', is made up of sublists with each containing a line from the 'records.csv' text file. So the first sublist, for example is ['11', ' Owen', 17]. I already found the max 'points' from all the sublists, 35 in this case, and would like to be able to identify the sublist that contains that element, and then print elements from said sublist. Any help is appreciated, thank you.

Answer 1

Have updated your code to do what is required

def getFileName():

    fileName = input('Input File Name: ')
    return fileName

def processFile(fileName):

    file = open(fileName, 'r')

    lines = file.readlines()

    fileList = []
    info = []
    pts = []

    for a in lines:
        fileList = a.split(',')
        fileList[-1] = int(fileList[-1])

        info.append(fileList)

    print('-----------------------------------------------')
    print('##\t Player\t             Points')
    print('-----------------------------------------------')

    for a in info:
        print(a[0],'.','\t', a[1],'\t\t', a[-1], sep='')
    print('-----------------------------------------------')

    for a in info:
        pts.append(a[-1])

    maxPts = max(pts)
    index=pts.index(maxPts) #this finds index of the element with higest score

    a=info[index] 
    print(a[0],'.','\t', a[1],'\t\t', a[-1], sep='') #prints the list with higest score
    print


    # Find maxPts in one of the 5 sublist, and make a brand new list of it.


    print('Top Scorer:', 'Points:', maxPts)

    file.close()

def main():

    fileName = getFileName()
    processFile(fileName)

main()

Answer 2

If you only need a min or max value, it is cheapest to sort the list and then get the value that you need.

info = [
  [0, "a", 121],
  [1, "aa", 14],
  [2, "b", 55]
]

print(sorted(info, key=lambda x:x[2])[0])
print(sorted(info, key=lambda x:x[2])[-1])

Answer 3

I am writing the logic, you can put it into function:

f=open('records.csv','r')
filecontent = f.readlines()
lists = [line.strip('\n').split(',') for line in filecontent if line.strip('\n')]
maxpts_sublst = max(lists,key = lambda x:int(x[-1]))
print("Top scorer: {0}, Points {1}".format(*maxpts_sublst[1:]))
f.close()

Output:

Top scorer:  Ryan, Points  35